1. Field of the Invention
This invention relates to a recording/reproducing apparatus for recording/reproducing video/audio data, and more particularly to a recording/reproducing apparatus which converts the bit rate of video/audio data so that the video/audio data can be copied in a detachable recording medium at a high speed, and automatically cancel recorded video/audio data to prevent shortage in an empty capacity of a storage region of a recording medium.
2. Description of the Related Art
In recent years, television broadcasting has been digitized so that a television broadcasting program with a high image-quality or enhanced-definition in the digital broadcasting can be watched or viewed. However, the video/audio data with enhanced-definition has a very large quantity of data. For example, in the case of the video/audio data with a bit rate of 24 Mbps, the data quantity of the video/audio data for one hour is about 10.5 GB. In order to record such video/audio data, a large-capacity HDD (Hard Disk Drive) is required. Further, a DVD-R (Digital Versatile Disk-Recordable) and a DVD-RW (Digital Versatile Disk-ReWritable), because they have a storage capacity is 4.7 GB, can record the video/audio data for only about 27 minutes at the bit rate of 24 Mbps. Therefore, in copying the video/audio data with enhanced-definition recorded in the HDD, the bit rate of the video/audio data with enhanced-definition recorded in the HDD must be converted to provide a video/audio signal at a low bit rate to be copied in the DVD. Thus, in order to implement the copying, the working time approximately equal to the time taken for recording was required. Further, even with the large-capacity HDD, it has a limited storage region. This presents a problem that if a user does not erase the video/audio data recorded in the storage region of the HDD as the need arises, the storage region of the HDD becomes insufficient so that a television broadcasting program cannot be recorded in the storage region of the HDD.
As a background art, there has been proposed a technique for recording video/audio data encoded from a video/audio signal on a recording medium, reproducing the video/audio signal decoded from the video/audio data recorded on the recording medium and copying the video/audio data encoded again from the decoded video/audio signal on the recording medium at a high speed (for example, see JP-A-2003-224813).
Further, there has been also proposed a technique for reading information data in a shorter time than a real reproducing time from a detachable device for recording information data, writing the information data thus read in a disk recording medium and outputting the information data as reproduced data simultaneously with writing (for example, see JP-A-2003-249008).
Further, there has been also proposed a technique for acquiring an encoded statistical quantity, which is employed when image quality conversion embedded at predetermined intervals will be executed afterwards, in a stream of image data accumulated in a recording medium, and converting the image data into the image data with enhanced-definition on the basis of the encoded statistical quantity (for example, see JP-A-2003-324680).
Further, there has been also proposed a technique for changing digital data between the digital data of an external input signal and the digital data decoded from recorded data on the basis of an user's instruction, encoding one of the digital data of the external input signal and the digital data decoded from the recorded data and copying the encoded digital data while it is format-converted (for example, JP-A-2003-109307).
Furthermore, there has been also proposed a technique for setting a recording-holding condition of a broadcasting program to be recorded in order to record the broadcasting program with data relative to the recording-holding condition on a recording medium and checking the data relative to the recording-holding condition already recorded in order to erase the broadcasting program not satisfying the recording-holding condition among the broadcasting programs recorded on the recording medium (for example, JP-A-2003-289490).